The gray screen issue in HP MediaSmart Webcam on an HP Pavilion g series could be resolved by trying the following steps:
- Make sure the webcam is enabled in the BIOS settings.
- Update the webcam driver from the HP website or through Device Manager.
- Restart the computer and check if the issue is resolved.
- If the problem persists, try reinstalling the HP MediaSmart Webcam software.
- If none of the above steps work, it might be a hardware issue, and contacting HP support would be recommended.